Monomethylol dimethyl hydantoin to shrinkproof cellulose fabrics



Patented July 1, 1952 MONOMETHYLUL DIMETHYL HYDANTOIN TO SHRINKPROOFCELLULOSE FABRICS Leo Beer, Montreal, Quebec, Canada No Drawing.Application December 1, .1949, Se-

rial No. 130,609. 1949 INTRQDUCTION This invention relates to thechemical shrinkage control of textile fabrics.

The process is applicable to' cellulosic textiles. They may be made fromnatural cellulose or regenerated cellulose or mixtures of one or both ofthe said types with up to about 50% of a cellulose ester of an organicacid, for example, cellulose acetate.

PRIOR ART Many attempts have been made to develop and perfect processeswhich control the shrinkage of such fabrics. For this purpose, fabricshave been treated with monoor dialdehydes such as formaldehyde orglyoxal in the presence of acids or in the presence of a salt which isacid reacting per se or becomes acid during processing, for example,during baking at elevated temperature. This results in deterioration intensile strengths and abrasion resistance which is especially serious inthe case of cotton and is often accompanied by discoloration.

The aldehyde is applied either as a watery solution or as a compoundwhich only splits off the bound aldehyde by treating with acid or in thepresence of a salt which is acid or becomes acid at elevatedtemperature. Compounds like hexamethylentetramine, for instance, requirethe stoechiometric quantity of acid for their complete decomposition. Ifthe quantity of acid for this purpose is not sufficient, the excess ofhexamethylentetramine acts as a buffer and counteracts the reactionbetween the aldehyde and the cellulosic material, and as a result, theintended effect is unsatisfactory.

Despite this, hexamethylentetramine has been recommended as a protectiveagent. In British Patent 460,201 (1936) the inventors recommend adding acertain quantity of hexamethylentetra-mine to the impregnating baths toprotect the cellulosic material against the destructive action of thefree acids. The reaction takes place as follows:

Other acids can be used. V

The applicant in U. S. Patent 2,441,859 recommends the decomposition ofthe hexamethylentetramine with volatile organic acids by steaming thefabrics, previously impregnated with a watery solution ofhexamethylentetramine and dried, in a steam chamber, in the presence ofan excess of acetic or formic acid. Y

2 Claims. (Cl. 8----116.3)

In Canada November 22,

If watery solutions of aldehydes in the presence of an acid, forcatalizing the reaction are applied, certain disagreeable disadvantagesare well-known. Working with formaldehyde solu- I tions, is, besideother unfavourable consequences, a very unpleasant operation at alltimes. Therefore; more recently, 5 the application of glyoxal has beenrecommended. According to U. S. Patent 2,436,076, 'glyoxal is used,preferably in the presence of oxalic acid with subsequent dryingand-baking the goods at elevated temperature. But, whereas rayon fabricsare made shrink-proof to 'a satisfactory degree and the shrinkagetendency significantly curbed in the case of cotton fabrics, the formerdisplay a loss in the range of 20% in tensile strength and the latter inthe range of 50%.

In following the procedure of the applicants co-pending U. S. patentapplications 722,955, filed January 18, 1947, now U. S. Patent No.2,484,545,

mally prior to the anti-shrink procedure, only certain types ofdye-stuffs can be used. In the present process, the treated fabric needonly be neutralized and washed for a short time, for example, from about5 to about 10 minutes at about 35 C. to 45 C.

' OBJECTS It is the object of the present invention to eliminate thementioned disadvantages and inconveniences by treating textile fabricswhich are formed predominantly of natural cellulosic materials orregenerated cellulose, including mixtures containing up to about 50% ofcellulose acetate fibres with dilute aqueous solutions of a specifictype of aldehyde compound which gives off the bound aldehyde by treatingeither with acid solutions or in an alkaline medium, for stabilizingthem against shrinkage but with no appreciable loss, in tensile strengthand having an increased resistance to abrasion without any tendency todiSCOlOIiIlg by baking-curing.

APPLICANTS DEVELOPMENT The applicant has now found that this objectdition to release much of the formaldehyde. n

the other hand, the monomethylol dimethyl hydantoin gives off all thebound formaldehyde under milder conditions. v Therefore, itisthepreferred formaldehyde donor. It contains 18.98% combme f rmaldehydewhich is vai able chemic l u e. tis ver solub e .i w ter, and s lits ofthe form ldehyde as wel u de alkaline conditions as ac drnedia- .llb ierated forma deh e in st tu nasccnd issreact s w th he cellu ose at eeva ed temperatu e- Usin the e-mentioned sub t nces, unde a aline con tn the r action pro u form b t-ween th fo ma dehyde a d the ce lu ose-inot v r stab e, wher asqu ra co ditio s probabl po voxymethv enebt er lkages are term d h cha e t bl to y rol sisand a ch ract iz d by a r ducd, we ng cap c y wh n oak d n aterland t r e reduce the sh in a e d n yo th re ed eellulosic material. If the treatment is carried out undercontrolled conditionstheifabr-ics;show no appreciable loss intensilestreng-th. An improved reslstance to abrasi n willi esult andthereis not even the slightest tendency-for discoloring. ,Dim th lhydantoin robably remainsas a y- -;I utt imp-the t at fa ric a ter baing w ich be easily removedby a short-washing opera tion. The f e. a ict eat d by this ew method show no tendency.toward-.chlonne retention.

.Ithau ers-spec fic obi e o thcpresen nven i n o s ure I tabilization ofa the aforesaid types o t tile fa rics against shr nkage but withoutsignificantly impairing their tensile stren th and mprov ng their a a onresistance wher in the fibers are wetteu with dilute watery solution ofmonomethylol dimethyl 'hydantoin. dr e andsub eque tly baked at 1 0C.-or hi h until the desired shrinkage control has beenisecured, i. e. asubstantial reaction between the cellulose and the liberatedformaldehyde has taken place.

Other objects and features of the invention will be apparent from thefollowing description. Broadly speaking, the invention includescmploying nearly neutralaqueous solutions of monomethylol dimethylhydantoin in the presence of a non-volatile organic acid catalystcapable of giving these solutions a -pI-I from about 2 to'about 2. 5.Suitable acids are for example, oxa c acid, lactic acid, citric acid,tartaric acid and other non-volatile organic acids or mixtures thereofstrong enough to catalyze the reaction'between the aldehyde and thetextile material. The acid must be such as to give a pH within the rangefrom about 2 to about 2.5 which is a preferred range of the invention.The formaldehyde cellulose reaction must take place within the fibres ofthe natural or regenerated cellulose.

other means allowing a pick-up of a predeter- .mmedperoentage such as100% liquid retention According to the invention, any form of the 15 onthe basis of the dry weight of the goods. They are then tensionlessdried and finally cured or balzedfor about 2 to 5 minutes.

A drying rangeof to C. and a baking temperature within C. to C. isusually preferred. However, the exact formulation of the solution as tocomponents and strength as well as the conditions of drying and, bakingmay vary depending pon the construction, composition and form of'the'textile material. After curing, the fabrics are neutralized with analkali, for example, soda ash, eventually soaped, rinsed,hydro-extracted and dried without tension be- ;fore putting intoindustrial channels of trade. or

before making the physical measurementsreif erred to in the comparativetests below.

Before treatment of the fabric all traces .of starch, gums, glue ornatural resins and other sizing agents should be removed in order topermit the aqueous treating solution to penetrate the fabrics and enterthe heart of the fibres.

Whereshrinkage control of fabrics is desired. the dimensions at whichthe. fabrics are finally dried must be predetermined by a preliminarywash test. 'If desired, t e hand or body of the goods treated can bemodified in the direction of either softness or .a stiffer finish atwill by the introduction to the impregnatin baths of suitableagents suchas cation softeners for the formereffect or such vegetable or animalcolloids as starches, ums, glues, gelatines, modified starches, orsolutions or dispersions .of polyvinyl alcohol, etc. forthc lattereffect. The procass is usually carried out inthe absence .ofianyPhenolic, or -amidic compounds capable of formingresinous bodies withaldehyde under the conditions.

When fabrics are treated by this new method in theabsence of phenolic oramidiccompounds, theydo not show any tendency toward chlorine retention.Fabrics treated by the present invention are characterized by permanentstability against shrinkage and even successive washings at the boil .donot affect the results.

In the aqueous wettingasolution the suggested range of concentration ofthe monomethylol dimethyl hydantoin is 1%. to 7.5% inclusive(preferably; to 5% inclusive) basedupon the weight of the treatingsolution. The amount of the stabilizing compound or compounds employedis such as to furnish from about 2% to about 1.5% (preferably about 2%to about 1.0%) of active available formaldehyde based on the weight .ofthe aqueous solution.

Fabrics of viscose or .cuprammonium yarns so processed are furtherimproved as borne out by the fact that they show less tendency to fuzzduring washing as compared to an untreated material similarly washed.

This invention will be more clearly understood by reference to thefollowing examples. It is to be understood, however, that these examplesare merely illustrative of the process and that the invention is notlimited thereto, but rather is defined in'the appended claims. In theexamples, the term check has the meaning of untreated or originalmaterial.

EXAMPLE 1 C. Cotton R. Spun Rayon Monomethylol Dimethyl, g Hydantoin, gOxalic Acid Anhydrous Sodium, g Sulphate Igepal CTA Extra Water to make.

The fabric was subjected to treatment to remove any traces of starch,gums, glue, natural resins or other sizing agents present and dried. Itwas then passed through an aqueous impregnating solution of the abovecomposition. The solution had a pH of about 2.2. After the fabric waspassed through the solution and was well wetted out (this required about5 seconds immersion) it was squeezed to remove solution inexcess of 100%pick-up based on the dry weight of the fabric. It was then dried withouttension on a pin-tenter frame in air at about 83 C. to the dimensionsthat the fabric possessed before impregnating. The dried, tenteredfabric was then cured in circulating air at about 135 C. for about 5minutes in the case of the cotton and at about 149 C. for about 3minutes in the case of rayon. 5

' The fabric after curing was removed from the tenter frame and soaped,rinsed, hydroextracted, and dried without tension. To me'asure theirshrinkage in washing, samples were amen Warp Tensile Strength Abrasion(Taber Cycles) (inlb a) 0 Cotton R Rayon .0 Cotton QR Rayon As it can beseen'by the results obtained. the

' amount of NaSOa addedto 'thebath'has not to be exaggerated, especiallyin manage-er [stabilizing rayon fabrics but good results in everyrespect are achieved if carnea-durnndr the right conditions.

fabric were treated respectively for the purpose of obtainingshrink-proof efiects with aqueous solutions of the followingcompositions.- The check was not treated. I Monomethylol dimethyl'hydantoin 1 'grams25 The samples were immersed with the above solutionsas described in Example #1 and after drying cured.

Cotton .4 minutes at j i Spun rayon 3 minutes at V 149 and washed anddried as previously described.

laundered together with the check sample by 45 C Cotton the accelerated1 hour wash test described in U. S. A. Federal specification CCC-T-lQlACotp Shrinkage (i per sesdl ton Wash Test. f

Other samples were subjected to tensile sample Identm. Treatedd. IHourss from Gain over 5 :Wash on a1 Corn esi strengths and abrasionresistance measurements. 0 Scmmd Test r6551. shr i im The followingshrinkages were observed based upon the measurements. Check 8.5 -5.5-5.5 #1 a. 1 0. a s. 9 1.6

-3.1 0.9 4 1 (2'. Cotton [Warp Shrinkage in percentages] R- RAYON (EPUN)Treated lHour Loss from Gain over 8- 25 12.5 g gi and Wash Originalcompressive 0 Secured Test Length shrinkage 5 0. 2 5. 2 7. 3

5. 5. 8'26 W T n 11 St gth arp e S 6, Ten 45 78 L 22 (mlbs) Abrasion(Taber Cycles) -0.5 as 1.1 -;o.1 -4.o4 0.91 65 0 g3 4 13 0,37 CCottonRRayon OCOtton RRayon Check 54 65 soc-e 200-250 R. SPUN RAYON #1 4s 61825-850 600 -9.17 12.7 3.3 8 In all cases, a very good stablizationefiect is -4.11 -0.56 obtained. Moderate loss in tensile strength on :22in? cotton material. No loss in tensile strength in -4.5 -4.17 rayonmaterial. In both cases considerable'improved abrasion resistance.

V as 3 'ojusgs mnq spr the following composition. The

check wa not treated.

described in Exam le 1 and mine-d vat-tel, d ying for i, rmlnut eai lif'qe. Wa h d and dried s-n v u iy-d scr bed-in Ex mple I [WarpShrinkage (in percentagesJ] The achieved stabilization eiiect is verysatisfactory, practically without any change in tensile strength-andwithout any discoloring effect.

I 1a m;. ,t

.1- ma Process of sh nka e cont l a t xtil fabric selected from thegroup consisting of natural cellulose, regenerated cellulose and theirmixtures with up to about 50% of cel1ulose aceitate, the steps ofimpregnating said fabric vwith an aqueous solution of monomethyioldimethyl substantially retained nydannmisam aq o tio q a ina mm 11. to 7by weight -of monomethylol dim-ethyl hydantoin which, upon bakindecomposes to form from 0.2 to 1.5% of available active formaldehyde andcontaining a non-volatile organic acid in an amount such as to give tothe solution a pH of from about 2 to about 2.5, squeezing the surplusliquid from the fabric, drying said fabric, baking the dried fabric at atemperature of from to C. =for a time sufficient to effect reactio'n'between liberated formaldehyde and the textile fabric; and neutralizingand Washing said i'abrict'o remove acid and reaction Joy-productsthereby to provide a fabric which has substantially permanent stabilityagainst shrinkage in successive washings at the boil and which has itscolor and tensile strength.

2. The process of claim l, wherein the nonvolatile organic acid isselected from the group consisting of oxalic acid, lactic acid, citricacid,

and tartaric acid.

LEO BEEB.

R F RENCES CITED The following references are of record in the file ofhthis patent: v r A .7

UNITED STATES PATENTS OTHER REFERENCES Chemical and Engineering News,November 3, 1947, page 3243, and February 9, 1948,11, 4'15.

1. IN A PROCESS OF SHRINKAGE CONTROL OF A TEXTILE FABRIC SELECTED FROMTHE GROUP CONSISTING OF NATURAL CELLULOSE, REGENERATED CELLULOSE ANDTHEIR MIXTURES WITH UP TO ABOUT 50% OF CELLULOSE ACETATE, THE STEPS OFIMPREGNATING SAID FABRIC WITH AN AQUEOUS SOLUTION OF MONOMETHYLOLDIMETHYL HYDANTOIN, SAID AQUEOUS SOLUTION CONTAINING FROM 1 TO 7% BYWEIGHT OF MONOMETHYLOL DIMETHYL HYDANTOIN WHICH, UPON BAKING, DECOMPOSESTO FORM FROM 0.2 TO 1.5% OF AVAILABLE ACTIVE FORMALDEHYDE AND CONTAININGA NON-VOLATILE ORGANIC ACID IN AN AMOUNT SUCH AS TO GIVE THE SOLUTION APH OF FROM ABOUT 2 TO ABOUT 2.5, SQUEEZING THE SURPLUS LIQUID FROM THEFABRIC, DRYING SAID FABRIC BAKING THE DRIED FABRIC AT A TEMPERATURE OFFROM 120 TO 150* C. FOR A TIME SUFFICIENT TO EFFECT REACTION BETWEENLIBERATED FORMALDEHYDE AND THE TEXTILE FABRIC, AND NEUTRALIZING ANDWASHING SAID FABRIC TO REMOVE ACID AND REACTION BY-PRODUCTS THEREBY TOPROVIDE A FABRIC WHICH HAS SUBSTANTIALLY PERMANENT STABILITY AGAINSTSHRINKAGE IN SUCCESSIVE WASHINGS AT THE BOIL AND WHICH HAS SUBSTANTIALLYRETAINED ITS COLOR AND TENSILE STRENGTH.